The invention relates to an apparatus, such as a recording and/or reproducing apparatus having a mechanism for actuating an apparatus part in response to movement of a latching button, and a control for inhibiting the actuation of the part; and more particularly to such an apparatus comprising at least one button which is movable from an off-position to an on-position against the force of a return spring for selecting a mode of operation in the apparatus, and at least one apparatus part which is movable from a rest position to an operating position by setting the button from its off-position to its on-position and which starts that mode of operation in its operating position. An actuating device transmits the button actuating movement to the apparatus part. A latching member for the button is movable between a release position, and a latching position and retains the button in its on-position against the force of the return spring when the member is in its latching position. At least one control member, which is movable between a release position and a blocking position in which that mode of operation can be started or is inhibited, respectively, in its blocking position inhibits the movement of the latching member to its latching position, and inhibits the transmission by the actuating device of the button actuating movement to the apparatus part, thereby inhibiting movement of that part into its operating position.
Such an apparatus is disclosed in, for example, German Auslegeschrift No. 26 58 603, to which U.S. Pat. No. 4,106,064 corresponds. In this known apparatus the control member is constructed as a slide which is intended for sensing a marker, such as a break-out tab, of a magnetic-tape cassette. The member or slide cooperates directly with the actuating device, constituted by a shift lever, for controlling the slide; and cooperates with the latching member for controlling the button. Thus, the control member performs two control functions which must be coordinated accurately with one another for a correct operation. This requires a rather intricate construction of the control member. Since the control member cooperates with and controls the actuating device it may happen that in the event of erroneous control, for example, due to wear, the apparatus part performs an undesired movement although the control member is in its blocking position. Such a malfunction is obviously undesirable. Since the control member cooperates with the latching member and enables this latching member to retain the button in its on-position, if a cassette marker is sensed and the control member is consequently in its release position, the apparatus part constituted by the magnetic-head support is set to its operating position via the shift lever when a button is actuated to select the mode of operation. The button is retained in its on-position by the latching member. The fact that the button is retained in its on-position then provides an indication to the user that the apparatus has been set to the mode of operation. However, due to defects or incorrect operation it may also happen that the apparatus part is not set to its operating position when the button is actuated; that is, the apparatus part remains in its rest position and the mode of operation is not started, although the latching member keeps the button in its off-position. If the button is then retained in its on-position the user will erroneously assume that the mode of operation has been started. It is obvious that this is also undesirable.